package com.jcompressor.utils;

/*
 * Copyright (c) 2011, Scott Carnett
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * * Redistributions of source code must retain the above copyright notice, this list of conditions and the
 * following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
 * following disclaimerin the documentation and/or other materials provided with the distribution.
 * * Neither the name of jcompressor nor the names of its contributors may be used to endorse or promote products
 * derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import java.io.InputStream;
import java.util.Enumeration;
import java.util.List;
import java.util.NoSuchElementException;

import com.jcompressor.assertion.AssertArgument;

/**
 * @author Scott Carnett
 */
public class ListOfFiles implements Enumeration<InputStream> {
	
	private List<InputStream> streams;
	private int current = 0;
	
	/**
	 * The default constructor
	 * @param streams the input streams
	 */
	public ListOfFiles(final List<InputStream> streams) {
		AssertArgument.isNotNull(streams, "streams");
		this.streams = streams;
	}
	
	/**
	 * @see java.util.Enumeration#hasMoreElements()
	 */
	@Override
	public boolean hasMoreElements() {
		return((this.current < this.streams.size()) ? true : false);
	}
	
	/**
	 * @see java.util.Enumeration#nextElement()
	 */
	@Override
	public InputStream nextElement() {
		InputStream stream = null;
		
		if (!hasMoreElements()) {
			throw new NoSuchElementException("No more streams");
		}
		else {
			final InputStream nextElement = this.streams.get(this.current);
			this.current++;
			stream = nextElement;
		}
		
		return stream;
	}
	
	/**
	 * Gets the stream count
	 * @return int with the stream count
	 */
	public int size() {
		return this.streams.size();
	}
	
}